The present invention relates to a drive apparatus for a sunroof apparatus for a vehicle.
As shown in FIG. 12, a conventional type sliding sunroof includes rails 101 secured to a vehicle's body, and a sunroof panel 102 adapted to be slid along the rails 101 by an operation of a drive apparatus 103 to open or close an opening 104 of a roof 105. A driving power from the drive apparatus is transmitted to the sunroof panel 102 through a driven mechanism thereof.
Conventionally, as this kind of the drive apparatus for the sunroof, there has been known a structure shown in Japanese Patent Laid-Open Publication No. Hei 4-138917 (1992) and Japanese Utility Model Laid-Open Publication No. Hei 7-21418 (1995).
Both the conventional apparatuses are structured such as to have a rotary output shaft to which an output gear of a drive means is secured through a first reduction gear, and a detecting mechanism for detecting a moving position of the driven mechanism in synchronous with a rotation of the output shaft. The rotary output shaft is connected to the sunroof panel through the driven mechanism. The driven mechanism has a rotatable shaft separated or branched from the first reduction gear, and a second reduction gear disposed between the rotatable shaft and the first reduction gear.
The second reduction gear in the former conventional apparatus is constituted by a planetary gear structure comprising an internal gear and an external gear meshed with the internal gear and having a number of gear teeth which is one or more less than that of the internal gear, and the detecting mechanism is constituted such as to have a cam plate connected to the external gear by a plurality of cylindrical projecting portions and a plurality of hole portions to which the cylindrical projecting portions are loosely fitted, and a plurality of limit switches capable of being in contact with the cam plate.
The second reduction gear in the latter conventional apparatus is constituted by a planetary gear structure comprising a plurality of spur gears meshed with each other, and the detecting mechanism is constructed such as to have a contact element fixed to a final spur gear of the second reduction gear and an electrically conductive pattern member capable of being in electrical contact with the contact element in accordance with a rotation of the final spur gear.
However, in the conventional apparatus mentioned above, since the detecting mechanism has the shaft which is branched from the first reduction gear through the second reduction gear, the detecting gear is arranged on the different axis from the axis of the output gear. Accordingly, the apparatus itself is made large, and becomes disadvantageous in view of a space. Further, in the former conventional apparatus, since the limit switch is used for the detecting mechanism, especially, the apparatus is made large in a thickness direction, and further, in the latter conventional apparatus, since a plurality of spur gears are used for the second reduction gear, especially, the apparatus is made large in a plane direction.